1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same. More specifically, the present invention relates to a semiconductor device with a ferroelectric device and a method of manufacturing the same.
2. Background Information
A related example of a semiconductor device with a ferroelectric capacitor is described in Japanese Patent Publication JP-A-2002-252336, which is hereby incorporated by reference. In the semiconductor device, a ferroelectric capacitor is formed by laminating a lower electrode, a ferroelectric film, and an upper electrode, on a first insulating film in that order. The ferroelectric capacitor is covered with a second insulating film. An opening that exposes an upper electrode is formed in the second insulating film. In addition, a conductive barrier film and a conductive hydrogen barrier film are deposited or formed in that order, and patterned to have a region that includes an opening. Then a wiring layer is formed on the conductive hydrogen barrier film and the second insulating film. In the semiconductor device, the conductive barrier film and the conductive hydrogen barrier film are formed on the upper electrode exposed in the opening. Therefore, this structure prevents hydrogen and moisture generated in a later process from filtering through the upper electrode. As a result, deterioration of the ferroelectric film is prevented.
For example, in forming a wiring layer with wiring material including Al (aluminum), hydrogen is generated when moisture generated in a resist ashing process after the patterning of wiring chemically reacts with wiring material (Al) inside the wiring layer. To prevent the hydrogen generated in the wiring layer from reaching the upper electrode, the conductive barrier film and the conductive hydrogen barrier film are formed at a location between the upper electrode and wiring layer in the manufacturing process described above. However, in the manufacturing process, the wiring layer is formed after patterning the conductive barrier film and the conductive hydrogen barrier film, and a part of the wiring layer is directly formed on the second insulating film. In this structure, there is a possibility that hydrogen generated in the wiring layer filters through the second insulating film, enters the upper electrode and the ferroelectric film, and deteriorates the ferroelectric film.
In view of the above, there exists a need for an improved semiconductor and a method of manufacturing the semiconductor device, which can inhibit deterioration of the ferroelectric film caused by hydrogen generated from the wiring layer. This invention addresses this need in the related art as well as other needs, which will become apparent to those skilled in the art from this disclosure.